Semipermeable membrane of phenoxy resin containing sulfuric acid groups or salts thereof

ABSTRACT

A semipermeable membrane composed of a water-insoluble, membrane-forming polymer (hereinafter referred to as &#34;polymer (II)&#34;) which is obtained by partially converting the hydroxyl groups of a polymer represented by the following formula (hereinafter referred to as &#34;polymer (I)&#34;): ##STR1## wherein R and R&#39; are halogen, nitro, methyl or ethyl, X stands for a divalent group selected from methylene, ethylene, isopropylidene, ether (--O--), carbonyl (--CO--), sulfide (--S--), sulfoxide (--SO--) and sulfone (--SO 2  --), l and m are integers of from 0 to 4, p is 0 or 1, and n is an integer of from 100 to 1000, 
     to sulfuric acid groups or alkali metal, ammonium or nitrogen-containing basic organic compound salts thereof.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semipermeable membrane made of aspecial polymer.

2. Description of the Prior Art

As a reverse osmosis membrane heretofore used for the desalination ofsea water and salt water and for the separation of various inorganicsalts and organic compounds from solutions, there is known a so-calledLoeb-type membrane made of hydrous acetyl cellulose and having anasymmetric structure including a dense and compact surface skin layerand a porous substrate layer. The Loeb-type membrane can be formed intoa plate-like product, a spiral coil, a tubular product or a hollowfiber. The Loeb membrane has a sufficiently high capacity for practicaluse. However, this membrane is disadvantageous because it is readilyhydrolyzed by an acid or alkali and/or it is readily decomposed bymicroorganisms. Accordingly, when the membrane is placed in practicaluse, the pH of the solution to be treated should be adjusted to from 3to 7 so that the acetyl cellulose will not be hydrolyzed. Further, whenthe membrane is not in use, it must be stored in an aqueous solution ofa fungicidal or bacteriostatic chemical.

As another example of a reverse osmosis membrane that is in practicaluse, there can be mentioned a reverse osmosis membrane in the form of ahollow fiber, which is made from an aromatic polyamide. This membrane isdisadvantageous because it is readily decomposed by a very small amountof chlorine. Therefore, chlorine must be removed from the solution thatis to be brought in contact with this type of membrane.

We have discovered a reverse osmosis semipermeable membrane possessingthe advantages of the Loeb membrane, but which eliminates theforegoing-described defects of the known membranes.

Since reverse osmosis is performed using a feed liquid which is under ahigh pressure, in order to maintain stable the properties of thesemipermeable membrane used for the reverse osmosis, it is necessarythat compaction of the semipermeable membrane should not occur in thepresence of water under a high pressure. Accordingly, a polymer suitablefor making the membrane should be stiff enough to resist high pressurein the presence of water and it should contain hydroxyl groups necessaryfor attaining a sufficient water permeation speed. For example, acommercially available phenoxy resin manufactured by Union CarbideCorporation and having the formula: ##STR2## is very stiff becausebenzene nuclei are present in the main chain of the polymer. Further,since the hydroxyl groups are present as side chains, this resin has ahydrophilic property.

We have examined the suitability of this phenoxy resin as a material formaking a reverse osmosis membrane. As a result, it was found that aphenoxy resin of the foregoing formula possesses an inferior hydrophilicproperty and the required water permeation speed of a reverse osmosismembrane cannot be attained therewith. Therefore, the phenoxy resin ofthe foregoing formula, per se, is not suitable as a material for makinga reverse osmosis semipermeable membrane. We have discovered, however,that when a semipermeable membrane is made of a polymer obtained bypartially replacing the hydroxyl groups of the phenoxy resin of theforegoing formula by at least one substituent selected from sulfoalkylether groups, sulfoaryl ether groups, sulfoaralkyl ether groups andsalts thereof with an alkali metal, ammonium or nitrogen-containingbasic organic compound, the semipermeable membrane has an excellentsemipermeable characteristic and the foregoing disadvantages of theconventional acetyl cellulose and aromatic polyamide membranes areovercome.

However, a membrane composed of a polymer formed by partially replacingthe hydroxyl groups of the phenoxy resin of the above-formula, with asulfoalkyl ether group, a sulfoaryl ether group and/or a sulfoaralkylether group is disadvantageous in that the reduction of the waterpermeability of this membrane with the passing of time is conspicuous incomparison with the conventional acetyl cellulose membrane and, hence,this membrane is inferior to the conventional acetyl cellulose membranewith respect to its resistance to compaction under pressure and itscreep resistance when used for a long time.

We have discovered a semipermeable membrane which is free from thesedefects. We have found that a polymer obtained by partially convertingthe hydroxyl groups of the phenoxy resin of the above-mentioned formulaby a sulfuric acid group or a salt thereof with an alkali metal, ammoniaor a nitrogen-containing basic organic compound, has an excellentwater-permeating property. Moreover, the disadvantages of theconventional acetyl cellulose and aromatic polyamide membranes, and themembranes of the above-mentioned polymers obtained by partiallyreplacing the hydroxyl groups by a sulfoalkyl ether group, a sulfoarylether group and/or a sulfoaralkyl ether group, are completely eliminatedin a semipermeable membrane made of this polymer. This polymer isunexpectedly superior as a membrane-forming material in comparison withthe conventional acetyl cellulose and aromatic polyamides, and theabove-mentioned modified phenoxy resin. We have now completed thepresent invention based on these findings.

More specifically, in accordance with the present invention, there isprovided a semipermeable membrane made of a water-insoluble,membrane-forming polymer, hereinafter referred to as "polymer (II)",which is obtained by partially converting the hydroxyl groups of apolymer having the following formula, hereinafter referred to as"polymer (I)": ##STR3## wherein R and R' are halogen, nitro, methyl orethyl, X is a divalent group selected from methylene, ethylene,isopropylidene, ether (--O--), carbonyl (--CO--), sulfide (--S--),sulfoxide (--SO--) and sulfone (--SO₂ --), l and m are integers of from0 to 4, p is 0 or 1, and n is an integer of from 100 to 1000, tosulfuric acid groups or salts thereof with an alkali metal, ammonium ora nitrogen-containing basic organic compound.

The term "semipermeable membrane", used in the specification and claims,means a membrane having a selective permeability, which can be used forsuch membrane separation processes as reverse osmosis, ultra-filtration,dialysis and electrodialysis.

The semipermeable membrane of the present invention will now bedescribed in detail.

The starting polymer (I) that is used for preparing the material polymer(II) used to make the semipermeable membrane of the present invention isa polymer obtained by reacting a dihydric phenol with epichlorohydrin(West German Patent Publication No. 1,545,071) or by reacting a phenoxyresin formed by reaction between a dihydric phenol and epichlorohydrin,with a dihydric phenol (British Pat. No. 980,509). The starting polymerhas the formula (I): ##STR4##

In the formula (I), R and R' each are halogen, particularly chloro orbromo, nitro, methyl or ethyl, and l and m are integers of from 0 to 4.When the number of the substituents R or R' is two or more, thesesubstituents can be the same or different. X is methylene, ethylene,isopropylidene, ether (--O--), carbonyl (--CO--), sulfide (--S--),sulfoxide (--SO--) or sulfone (--SO₂ --), and p is 0 or 1 and n is aninteger of from 100 to 1000.

Examples of suitable dihydric phenols are bisphenols such asbis(4-hydroxyphenyl)-methane, bis(4-hydroxy-3-methylphenyl)-methane,bis(4-hydroxy-3,5-dichlorophenyl)-methane, bis(4-hydroxyphenyl)-ketone,bis(4-hydroxydiphenyl)-sulfide, bis(4-hydroxyphenyl)-sulfone,4,4-dihydroxy-phenyl ether, 1,2-bis(4-hydroxyphenyl)-ethane,2,2-bis(4-hydroxyphenyl)-propane,2,2-bis(4-hydroxy-3-methylphenyl)-propane,2,2-bis(4-hydroxy-3-chlorophenyl)-propane,bis(4-hydroxyphenyl)-phenylmethane,bis(4-hydroxyphenyl)-diphenylmethane,bis(4-hydroxyphenyl)-4'-methylphenylmethane,1,1-bis(4-hydroxyphenyl)-2,2,2-trichloroethane,bis(4-hydroxyphenyl)-(4'-chlorophenyl)-methane,1,1-bis(4-hydroxyphenyl)-cyclohexane,bis(4-hydroxyphenyl)-cyclohexylmethane, 4,4'-dihydroxydiphenyl and2,2'-dihydroxydiphenyl. These bisphenols can be used singly or in theform of mixtures of two or more of them.

The polymer (II) used to make the semipermeable membrane of the presentinvention can be prepared by partially converting the hydroxyl groups ofthe starting polymer (I) having the above formula (I), to a sulfuricacid group, a salt thereof with an alkali metal, ammonium or anitrogen-containing basic organic compound or a mixture thereof. Thesubstituents formed by such conversion are represented by the followingformulae: ##STR5## wherein M is an alkali metal such as Na, K or Li, andA is ammonia or a nitrogen-containing basic organic compound such asaliphatic primary amines such as methylamine, ethylamine, propylamine,isopropylamine, butylamine, isobutylamine, sec-butylamine,tert-butylamine, pentylamine, isopentylamine, hexylamine,2-ethylhexylamine and laurylamine; aliphatic secondary amines such asdimethylamine, diethylamine, dipropylamine, diisopropylaminedibutylamine, N-methylethylamine and N-ethylisobutylamine; tertiaryamines such as trimethylamine, triethylamine, N,N-dimethylpropylamine,tributylamine and N-ethyl-N-methylbutylamine; mono-, di- andtri-ethanolamine; diethylaminoethanol; urea;β-dimethylaminopropionitrile; aliphatic quaternary ammonium compoundssuch as tetramethylammonium and tetraethylammonium; alicyclic aminecompounds such as cyclohexylamine, N,N-dimethylcyclohexylamine, anddicyclohexylamine; aromatic primary amines such as aniline, o-toluidine,m-toluidine, p-toluidine, o-ethylaniline, m-ethylaniline,p-ethylaniline, p-isopropylaniline and p-t-butylaniline; aromaticsecondary amines such as N-methylaniline, N-ethylaniline andN,N-dimethylaniline; aromatic quaternary ammonium compounds such astrimethylphenyl ammonium and ethyldimethylphenyl ammonium; aralkylamines such as benzylamine and α-methylbenzylamine; nitrogen-containinghetrocyclic compounds such as pyrrole, 1-methylpyrrole, indole,pyridine, α-picoline, β-picoline, γ-picoline, 2-ethylpyridine,quinoline, piperidine, 1-methylpiperidine, 2-methylpiperidine,1,8-diazabicyclo[5.4.0]undecene-7 and morpholine.

The conversion is generally accomplished by (1) dissolving the polymer(I) in a solvent, such as tetrahydrofuran, dioxane orN,N-dimethylformamide, (2) adding to the solution, at a temperaturelower than room temperature, chlorosulfonic acid or anhydrous sulfuricacid in an amount of from 15 to 100 mole %, based on the hydroxyl groupsof the starting polymer (I) and (3) conducting the reaction for 1 to 3hours. After completion of the reaction, the reaction mixture is addeddropwise into water or a non-solvent, such as an alcohol, whereby toprecipitate the resulting polymer, wherein the hydroxyl groups of thestarting polymer (I) have been transformed to ##STR6## groups. If ahydroxide of the above-mentioned alkali metal, or ammonia or anitrogen-containing basic organic compound as mentioned above is addedto the above reaction mixture in an amount of from 2.5 to 5 moles, permole of anhydrous sulfuric acid or chlorosulfonic acid used for thereaction, the substituted sulfuric acid group is converted to an alkalimetal salt, or ammonium salt or a quaternary ammonium salt of thenitrogen-containing basic organic compound. The recovered polymer iswashed with water and is dried, preferably at a temperature below 50° C.The sulfated phenoxy resin is readily hydrolyzed when the terminal groupis a sulfuric acid group (--OSO₃ H), and its stability is low when it isallowed to stand. However, if the terminal sulfuric acid group isconverted to a salt, the resin is stabilized. Therefore, it is preferredthat the sulfuric acid group is converted to an alkali metal salt, orammonium salt or a quaternary salt of a nitrogen-containing basicorganic compound.

The starting polymer (I) can be identified by NMR analysis and IRanalysis. Confirmation of the introduction of substituents present inthe polymer (II) of the present invention and determination of thequantity of the introduced substituents are performed by sulfur analysisof the sulfuric acid groups, NMR analysis of the substituted methinegroups or the organic compound forming the salt with the sulfuric acidgroup or by neutralizing titration.

The thus-obtained polymer (II) is a novel macromolecular compound which,so far as is known, is not disclosed in any literature reference.

The process for preparing a semipermeable membrane from thethus-obtained polymer (II) will now be described.

The casting process is most preferred for forming a membrane. Themembrane of the present invention can be uniform or homogeneous incross-section or it can be an asymmetric (skinned) membrane having animproved water-permeating property, which asymmetric membrane comprisesa dense and compact surface skin layer and a porous supporting layer,like a Loeb membrane. The membrane of the former (homogeneous) type canbe obtained by dissolving the polymer in a single solvent, casting thesolution onto a substrate having a smooth surface, such as a glasssheet, a metal plate, a sheet of a synthetic resin inert to the solventor a porous sheet, and then gradually evaporating the solvent in avessel covered with a filter paper or the like. The membrane of theasymmetric type is obtained by dissolving the polymer in a singlesolvent or a mixed solvent comprising at least two solvents differing intheir boiling points, casting the solution onto a substrate such as thesubstrates mentioned above, removing a part of the solvent byevaporation and treating the cast layer in a coagulating bath. As thesolvent, there can be mentioned those as listed in the following Table1.

Those solvents can be used singly or in the form of a mixed solventcomprising two or more of them.

A low-boiling-point organic compound having a good compatibility withsuch solvent and a non-solvent of the type used for the coagulating bathcan be added to the polymer solution prior to casting, provided that thesolubility of the polymer is not lowered. As such organic compound,there can be mentioned, for example, alcohols such as methanol, ethanoland isopropanol, ethers such as tetrahydrofuran and dioxane, and ketonessuch as acetone and methylethyl ketone. Also water can be used for thesame purpose. As the non-solvent used for the coagulating bath, water isordinarily used, but organic solvents having a coagulation value lowerthan 100, such as alcohols, e.g., methanol, ethanol and isopropylalcohol, can be used. The term coagulation value used herein indicatesthe amount (parts by weight) of the non-solvent or mixed non-solventnecessary for rendering opaque a solution containing 1% by weight of thepolymer, when the non-solvent or mixed non-solvent is gradually added to100 parts by weight of said polymer solution.

A composite (laminate-type) semipermeable membrane can be prepared byforming an ultra-thin membrane of the polymer (II) of the presentinvention on a preformed porous membrane. In this case, the preformedporous membrane used should have on the surface thereof pores having asize of up to 1μ, preferably up to 0.5μ and also it should not bedissolved in the solvent used in the casting solution.

As such porous membranes, there can be mentioned a porous polypropylenemembrane (manufactured and marketed under the tradename "Juraguard®" byPolyplastics K.K.), a porous polyphenylene-oxide membrane (manufacturedand marketed under the tradename "Neclepore®" by Nomura MicroscienceK.K.), and porous membranes composed of polysulfone, cellulosetriacetate and other synthetic resins. The ultrathin membrane of thepolymer (II) formed thereon has a thickness smaller than 3μ, preferablysmaller than 0.5μ. It can be a uniform (homogeneous) membrane or anasymmetric membrane comprised of a dense and compact surface skin layerand a porous underlying layer.

This composite semipermeable membrane is obtained by casting onto apreformed porous membrane, such as those mentioned above, a solutioncontaining 0.1 to 5% by weight, preferably 0.5 to 3% by weight, of thepolymer (II) dissolved in a single solvent or mixed solvent by means ofa glass rod or doctor blade, evaporating a part or all of the solvent,and dipping the coated porous membrane in a coagulating bath asmentioned above.

In the production of the polymer (II), 15 to 90%, preferably 20 to 85%,of the hydroxyl groups of the polymer (I) should be transformed tosulfuric acid groups or salts thereof with an alkali metal, ammonia ornitrogen-containing basic organic compound.

Thus, the polymer (II) has the formula ##STR7## wherein R, R', X, l, m,p and n have the same meanings as defined above, and wherein from 15 to90% of said D groups are sulfuric acid groups or salts thereof with analkali metal, ammonium or nitrogen-containing basic compound and thebalance of said D groups are hydroxyl groups.

The present inventors have found that the polymer (II) is remarkablyaffected in respect of its solubility, film-forming property andresistance to hydrolysis owing to the introduction of the sulfuric acidgroup or a salt thereof with an alkali metal, ammonium ornitrogen-containing basic organic compound, in place of the hydroxygroups of the polymer (I). The polymer (II) having only sulfuric acidgroups can be formed into films. However, it is somewhat susceptible tohydrolysis in the procedure used for the preservation and preparation ofthe film. It has been examined how the polymer (II) salt with sodium,ammonium, dimethylamine or pyridine is soluble in various solvents aslisted in Table 1. When the asymmetric film is prepared, the selectionof a solvent to be used is significant. In general, there can be used alarger number of solvents when the polymer (II) salt is a salt of anitrogen-containing basic organic compound such as pyridine anddimethylamine, than can be used with ammonium and sodium salts.

In addition, the polymer (II) salt with a nitrogen-containing basicorganic compound has a smaller rate of hydrolysis, according as the pKavalue of the nitrogen-containing basic organic compound is greater. Thehydrolysis is measured by allowing the polymer, in the form of flakes,to stand at 60° C., at 100% relative humidity for 20 days anddetermining the remaining amount of substitution. The results areillustrated in the drawing.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is a graph showing the remaining amount of substitutionversus the pKa value of the nitrogen-containing basic organic compoundused as the salt-forming moiety of polymer (II).

                                      Table 1                                     __________________________________________________________________________    SOLUBILITY OF POLYMERS II                                                                  Salt                                                                             pyridine                                                                           dimethylamine                                                                         ammonium                                                                            sodium                                     Solvent         salt salt    salt  salt                                       __________________________________________________________________________    N,N'-dimethylformamide                                                                        ○                                                                           ○                                                 N,N'-dimethylacetoamide                                                                       ○                                                                           ○                                                 dimethylsulfoxide                                                                             ○                                                                           ○                                                 hexamethylphosphoamide                                                                        ○                                                                           ○                                                                                    ○                                   2-pyrrolidone   ○                                                                           ○                                                                              ○                                                                            ○                                   formamide       ○                                                                           ○                                                                              ○                                                                            ○                                   pyridine        ○                                                                           ○                                                                              ○                                                                            Δ                                    dimethylaniline Δ                                                                            Δ ˜ x                                                                     x     x                                          furfuryl alcohol                                                                              ○                                                                           ○                                                                              Δ                                                                             x                                          furfural        ○                                                                           ○                                                                              x     x                                          2-ethoxyethanol ○                                                                           ○                                                 acetone         Δ                                                                            Δ x     x                                          dioxane         Δ ˜ x                                                                  Δ ˜ x                                                                     Δ ˜ x                                                                   Δ ˜ x                          methylal        ○ ˜ Δ                                                           Δ ˜ x                                                                     Δ ˜ x                                                                   x                                          anisol          Δ                                                                            Δ x     x                                          methanol        x    x*      x     x                                          isopropyl alcohol                                                                             Δ                                                                            Δ x     x                                          N-methylpyrrolidone                                                                           ○                                                                           ○                                                 tetramethylurea ○                                                                           ○                                                 ethylenecyanohydrin                                                                           ○                                                                           ○                                                 piperidine      Δ                                                                            Δ Δ                                                                             x                                          morpholine                         Δ                                    butyrolactone   ○                                                                           ○                                                 lutidine                           Δ                                    trimethyl phosphate                                                                           ○                                                      tetrahydrofurfuryl                                                            alcohol         ○                                                                           ○                                                 cyclohexylamine ○                                                                           Δ Δ                                                                             Δ                                    diacetone alcohol                                                                             ○                                                      aniline         ○                                                                           ○                                                 __________________________________________________________________________     Note:                                                                         *heated                                                                       Evaluation Criteria:                                                          ○ completely soluble                                                     soluble, however slightly muddy                                               soluble, however muddy                                                      Δ only swelled                                                           x insoluble                                                             

As the amount of the hydroxyl groups transformed to sulfuric acid orsalt groups to obtain polymer (II) is increased, the water content of auniform (homogeneous) membrane formed from the polymer (II) increasesand also the water flux rate of the uniform membrane increases, but themechanical strength of the uniform membrane when dipped in water isreduced.

The term "water content" referred to herein means the water content ofthe uniform (homogeneous) membrane which has been dipped in pure waterfor 3 days. The term "mechanical strength" used herein includes tensilestrength and tensile modulus.

When more than 85% of the hydroxyl groups are transformed to theabove-mentioned groups in the polymer (II), if a uniform (homogeneous)membrane prepared from this polymer (II) is dipped in water, themembrane becomes swollen and either the tensile strength or the tensilemodulus of the membrane is reduced to less than 10% of the tensilestrength or tensile modulus of a membrane made of the unsubstitutedstarting polymer (I) when the latter membrane is similarly dipped inwater. Accordingly, such membrane cannot be put into practical use.

The properties of the polymer (II) as a semipermeable membrane,according to this invention, can be modified by immersing it in anaqueous solution or an organic solvent which contains a cross-linkingagent in order to cross-link the polymer (II). As the cross-linkingagent, there can be used melamine resins such as dimethylolmelamine,trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine,hexamethylolmelamine and methoxy-, ethoxy-, propoxy- or butoxy-compoundsthereof and urea derivatives of the foregoing such as dimethylolurea,tetramethylolurea and urea resins of condensates thereof, benzoguanamineresins such as dimethylolbenzoguanamine anddimethoxymethylolbenzoguanamine, amino resins mixed therewith, aldehydessuch as formaldehyde, glyoxal, aldol and glycol aldehyde, and di- ortri-functional epoxides such as butadiene diepoxide, diglycidyl ether,glycol diglycidyl ether, glycerine diglycidyl ether, butanedioldiglycidyl ether, resorcinol diglycidyl ether andtris(epoxypropyl)isocyanurate. In addition, it can be cross-linked witha divalent cation such as calcium, magnesium and barium derived fromalkaline earth metal salts. The cross-linking improves thesemipermeability, reduction of swelling of the membrane owing to anorganic solvent, reduction of lowered membrane properties when it isused continuously for a long time and increase of mechanical strength.

If the amount of the hydroxyl groups transformed to the above-mentionedgroups is lower than 15%, the water flux rate of the resulting uniform(homogeneous) membrane is reduced, and the membrane cannot bepractically used as a reverse osmosis semipermeable membrane.

A uniform membrane of the polymer (II) of the present invention wasprepared according to the above-mentioned method and the separationcapacity of the membrane for aqueous solutions of variouslow-molecular-weight compounds was evaluated. In order to evaluate theseparation capacity, the water permeation coefficient and the soluteremoval ratio were measured. The water permeation coefficient isrepresented by the following formula: ##EQU1## And, the solute removalratio is represented by the following formula: ##EQU2##

The polymer (II) of the present invention has an excellent separationcapacity and is useful as a material for a reverse osmosis membrane. Ithas been found that the separation capacity of the membrane of thepresent invention is comparable to the separation capacity of an acetylcellulose membrane. As compounds that can be separated by the membraneof the present invention, there can be mentioned inorganic salts ofmono- to hexa-valent metals, such as halides, nitrates, sulfates,phosphates, chromates, borates and carbonates, and various naturalorganic compounds such as alcohols, ketones, phenols, carboxylic acidsand amines.

An acetyl cellulose membrane is readily oxidized by a chromate, and whenthe membrane is used for separation of chromates, deterioration of themembrane is caused and the properties of the membrane are degraded.Further, since the acetyl cellulose membrane has a very high affinitywith lower carboxylic acids, the removal ratio of such acids isextremely reduced or shows a negative value. In contrast, asemipermeable membrane prepared from the polymer (II) of the presentinvention is very stable against various chemicals and shows arelatively high removal ratio to carboxylic acids.

The semipermeable membrane according to the present invention can beused for desalination of sea water, salt water and brine, for thetertiary treatment of waste water from a plating plant, and for treatingpulp-containing waste water, waste water from a food processing plant,other various industrial waste waters and sewages, for desalination andpurification for producing of ultra-pure water, and for concentration ofsoy milk, milk, syrups and juices of fruits such as tomato, grape,orange and apple.

The present invention will now be further described in detail byreference to the following illustrative Examples.

EXAMPLE 1 (i) Sulfation of Phenoxy Resin (I):

In a 4-neck separable flask having a capacity of 1 liter and equippedwith a stirrer, a cooling pipe, a thermometer and a dropping funnel,60.0 g of a phenoxy resin (PKHK manufactured by Union CarbideCorporation; X in the formula (I) stands for an isopropylidene group, land m are zero and p is 1) was dissolved in 375.0 g ofN,N-dimethylformamide. While the flask was being cooled by ice water sothat the temperature of the solution was maintained below 25° C., 21.3 gof chlorosulfonic acid (purity=99%; 0.181 mole) was added dropwise tothe solution over a period of 40 minutes, and then, the reaction wasconducted at room temperature for 2 hours. Then, 33.3 g of pyridine(0.417 mole) was added dropwise to the reaction mixture over a period of15 minutes, and aging was then conducted for 30 minutes to complete thereaction. Then, 60 g of N,N-dimethylformamide was added to the reactionmixture, and the mixture was added dropwise to 6 l of water toprecipitate the polymer from the reaction mixture liquid. The formedpolymer solids were washed two times with 6 l of water, then separatedand recovered by a centrifugal separator, then dried at room temperaturefor 3 days by an air drier and further dried at 50° C. in vacuo for 1day. Confirmation of the introduction of sulfuric acid groups anddetermination of the degree of sulfation were performed by determinationof the pyridine nucleus proton in the NMR spectrum at 8-9 ppm, the Sanalysis and the neutralizing titration of electrolytic groups. It wasfound that the degree of substitution was 0.78 group per recurring unitand the electrolytic group capacity was 1.9 milligram equivalents.

(ii) Formation of Uniform (homogeneous) Membrane of Sulfated PhenoxyResin:

In 25.5 g of pyridine was dissolved 4.5 g of the sulfated phenoxy resinobtained in step (i) above, and in a thermostat tank maintained at 50°C., the solution was cast on a horizontal casting glass sheet by using adoctor blade having a slit spacing of 250μ. The solution-cast glasssheet was covered with a glass cylinder having a top portion coveredwith a filter paper. The cast solution was dried in this state at 50° C.for 72 hours to form a uniform (homogeneous) membrane. When the uniformmembrane was dipped in pure water for 3 hours, the water content was34.9% by weight. The tensile modulus of the membrane was 1.03×10⁵ psi.

(iii) Evaluation of Separation Capacity of Membrane:

The separation capacity of the uniform membrane of the sulfated phenoxyresin having a thickness of 29.5μ, which had been prepared in step (ii)above, was tested by using a circulation type reverse osmosis apparatusfor flat membranes (S. Sourirajan, Ind. Eng. Chem, Fundam., 3, 206(1964)), under a liquid feed pressure of 80 Kg/cm², using an aqueoussolution containing 3500 ppm of NaCl, an aqueous solution containing3500 ppm of Na₂ SO₄, an aqueous solution of 2500 ppm of urea and anaqueous solution containing 2500 ppm of sucrose, respectively. Theconcentrations of NaCl and Na₂ SO₄ were determined based on the electricconductivity, and the concentrations of urea and sucrose were determinedby a TOC (total carbon) measuring device manufactured by Yuasa DenchiK.K. The results obtained are shown in Table 2. From these results, itis seen that the rejection or removal ratio of the membrane obtained inthis Example is slightly lower than that of an acetyl cellulose membraneshown in Comparative Example 1 given hereinafter, but the water flux orwater permeation coefficient is much higher than that of the acetylcellulose membrane.

                  Table 2                                                         ______________________________________                                        CAPACITIES OF MEMBRANE OF EXAMPLE 1                                                           Capacities of Membrane                                        Run                   water flux    rejection                                 No.    Starting Solution                                                                            (cm.sup.2 /sec . atm)                                                                       (%)                                       ______________________________________                                        1      3500 ppm NaCl  9.4 × 10.sup.-10                                                                      95.5                                             aqueous solution                                                       2      3500 ppm Na.sub.2 SO.sub.4                                                                   8.1 × 10.sup.-10                                                                      97.6                                             aqueous solution                                                       3      2500 ppm urea  4.3 × 10.sup.-10                                                                      80.5                                             aqueous solution                                                       4      2500 ppm sucrose                                                                             3.3 × 10.sup.-10                                                                      94.2                                             aqueous solution                                                       ______________________________________                                    

Comparative Example 1

A uniform membrane of acetyl cellulose having a thickness of 17.9μ wasprepared in the same manner as described in step (ii) of Example 1except that acetyl cellulose (E-398-3 manufactured by Eastman Kodak Co.)was used instead of the sulfated phenoxy resin andN,N-dimethyl-formamide was used instead of pyridine. The properties ofthe resulting membrane were evaluated according to the method describedin step (iii) of Example 1 and the results shown in Table 3 wereobtained.

                  Table 3                                                         ______________________________________                                         CAPACITIES OF MEMBRANE OF                                                    COMPARATIVE EXAMPLE 1                                                                         Capacities of Membrane                                        Run                   water flux    rejection                                 No.    Starting Solution                                                                            (cm.sup.2 /sec . atm)                                                                       (%)                                       ______________________________________                                        1      3500 ppm NaCl  1.4 × 10.sup.-10                                                                      96.0                                             aqueous solution                                                       2      3500 ppm Na.sub.2 SO.sub.4                                                                   1.1 × 10.sup.-10                                                                      99.1                                             aqueous solution                                                       3      2500 ppm urea  2.5 × 10.sup.-10                                                                      90.0                                             aqueous solution                                                       4      2500 ppm sucrose                                                                             1.3 × 10.sup.-10                                                                      99.2                                             aqueous solution                                                       ______________________________________                                    

Comparative Example 2

In 60 ml of anhydrous N,N-dimethylacetamide was dissolved 5.72 g of thesame phenoxy resin as used in Example 1 (PKHK manufactured by UnionCarbide Corporation) in a nitrogen atmosphere, and 0.768 g of sodiumhydride (effective NaH=0.016 mole) dispersed in liquid paraffin wasadded to the solution and the reaction was conducted at 30° C. for 1hour. Then, 1.952 g of propane sultone was added to the reaction mixtureand the reaction was conducted at 30° C. for 3 hours. The reactionmixture liquid was filtered by a glass filter of G2 and the filtrate wasreprecipitated from isopropanol. The precipitated polymer was washedwith water for 30 minutes and dried. The degree of modification withsulfopropyl ether in the resulting polymer was determined by measurementof the propylene groups and titration of the electrolytic groups. It wasfound that the modification degree was 0.75 group per recurring unit ofthe phenoxy resin. In 25.5 g of N,N-dimethylformamide was dissolved 4.5g of the thus-obtained polymer, and in a thermostat tank maintained at50° C., the solution was cast onto a clean smooth horizontal glass sheetby using a doctor blade having a slit spacing of 250μ. The solution-castglass sheet was covered with a glass cylinder having one end coveredwith a filter paper and the solvent was gradually evaporated. In thismanner, drying was carried out at 50° C. for 72 hours. When theresulting film was dipped in pure water for 3 days, the water contentwas 35.2%, and the thickness was 29.7μ and the tensile modulus was1.08×10⁵ psi. The thus-obtained membrane and the membrane obtained inExample 1 were stored in the same manner as described above for a longtime, and the capacities of both the membranes were compared. Theresults shown in Table 4 were obtained.

                  Table 4                                                         ______________________________________                                        Capacities Of Membranes Of Example 1 And                                      Comparative Example 2 In Long-Time Reverse Osmosis                                                          Uniform                                                           Uniform     Membrane of                                                       Membrane    Comparative                                     Capacities        of Example 1                                                                              Example 2                                       ______________________________________                                        Capacity after                                                                3 days                                                                        NaCl Rejection (%)                                                                              97.8        97.3                                            Water Flux        7.4 × 10.sup.-10                                                                    2.0 × 10.sup.-10                          (cm.sup.2 /sec . atm)                                                         Capacity after                                                                60 days                                                                       NaCl Rejection (%)                                                                              97.5        95.2                                            Water Flux (cm.sup.2 /sec . atm)                                                                7.0 × 10.sup.-10                                                                    1.5 × 10.sup.-10                          Water Permeability                                                                              95          75                                              Retention Ratio (%)                                                           ______________________________________                                    

EXAMPLE 2

A polymer was prepared in the same manner as described in step (i) ofExample 1 except that 19.3 g of chlorosulfonic acid was used. Thepolymer was found to have a sulfation degree of 0.64 group per recurringunit and an electrolytic group capacity of 1.654 milligram equivalents.The separation capacity of a uniform membrane having a thickness of26.8μ, which had been prepared from this polymer, was characterized by awater flux of 7.20×10⁻¹⁰ cm² /sec.atm and an NaCl rejection of 95.8%when a 3500 ppm NaCl aqueous solution was used as the feed liquid.

EXAMPLE 3 (i) Synthesis of Phenoxysulfone Resin (X in the formula (I) is--SO₂ --, l and m are zero, and p is 1):

A 0.2-liter, 4-neck round-bottomed flask equipped with a stirring motor,stirring glass blades, a thermometer, a nitrogen gas-introducing openingand a cooling pipe was charged with 62.50 g (0.30 mole) ofbis-(4-hydroxyphenyl) sulfone, 27.76 g (0.3 mole) of epichlorohydrin,93.76 g of ethanol, 13.52 g (0.338 mole) of sodium hydroxide and 57.0 gof water, and while the mixture was maintained at 40° C., reaction wascarried out for 80 hours under agitation. Then, the mixture was heatedand refluxed for 1 hour, and 36 ml of monochlorobenzene was added andthe mixture was further refluxed for 2 hours. The polymer that separatedfrom the solution and solidified was taken out and was dissolved inN,N-dimethylformamide at a concentration of about 5% by weight. Thepolymer was precipitated from the resulting solution by using methanolas a non-solvent. The polymer was recovered, washed with water and driedin vacuo at 50° C. for 2 days. The yield of the polymer was 57%, and thepolymer had a reduced viscosity of 0.34 dl/g (as measured at a polymerconcentration of 0.25 g/dl in N,N-dimethylacetamide).

(ii) Sulfation of Phenoxysulfone Resin:

The sulfation was carried out in the same manner as described in step(i) of Example 1 except that 56.1 g of the above phenoxysulfone resinwas used instead of 60 g of the phenoxy resin used in Example 1 and theamount used of chlorosulfonic acid was changed from 21.3 g to 10.65 g.From the results of the NMR analysis and the neutralizing titration ofthe electrolytic groups, it was found that the thus-synthesized sulfatedphenoxysulfone resin had a substitution degree of 0.39 group perrecurring unit and an electrolytic group capacity of 1.06 milligramequivalents.

(iii) Evaluation of Separation Capacity of Membrane:

A uniform (homogeneous) membrane having a thickness of 25.9μ wasprepared from the polymer obtained in step (ii) above in the same manneras described in step (ii) of Example 1, and the separation capacity ofthis membrane was evaluated. It was found that the water flux was6.48×10⁻¹⁰ cm² /sec.atm and the NaCl rejection was 94.7%.

EXAMPLE 4 (i) Preparation of Porous Polysulfone Membrane:

In 225 g of N,N-dimethylformamide was dissolved 45 g of polysulfone(Polysulfone 1700 manufactured by Union Carbide Corporation), and thesolution was cast in a thickness of 0.18 mm (7 mil) on a glass sheet.Then, the cast layer was dipped in an aqueous solution containing 2% byweight of N,N-dimethylformamide, which was maintained at 25° C., toeffect gelation. After complete gelation, the membrane was taken out andair-dried at room temperature. The thus-obtained porous membrane had apore diameter of 0.2 to 2μ and a thickness of 0.15 mm.

(ii) Preparation of Composite Membrane:

In 97 g of 2-methoxyethanol was dissolved 3 g of the sulfated phenoxyresin obtained in step (i) of Example 1, and the resulting solution wascast in a thickness of about 10μ onto the porous polysulfone membraneobtained in step (i) above while rotating a glass rod. The solution-castporous membrane was dried in a thermostat tank maintained at 50° C. for3 minutes to evaporate the solvent, and it was then dipped in ice watermaintained at 0° C. for more than 30 minutes to obtain a compositemembrane.

(iii) Properties of Composite Membrane:

The separation capacity of the composite membrane obtained in step (ii)above was tested in a circulation type reverse osmosis device for flatmembranes, under a feed liquid pressure of 80 Kg/cm², by using a 3500ppm NaCl aqueous solution. It was found that the water flux was 0.39 m³/m².day and the NaCl rejection was 93.8%.

EXAMPLE 5

In a solution comprising 36.2 g of dioxane, 12.8 g of acetone, 7.0 g ofmaleic acid and 14.0 g of water there was dissolved 30 g of the sulfatedphenoxy resin obtained in step (i) of Example 1, and the resultingpolymer solution was cast onto a horizontal glass sheet by using adoctor blade having a slit spacing of 150μ. The film was dried at 20° C.for 30 seconds to evaporate a part of the solvent, and dipped in icewater maintained at 0° C. The thus-obtained asymmetric membrane wastested under a feed liquid pressure of 40 Kg/cm² in the same manner asdescribed in step (iii) of Example 1 except that the surface of themembrane on the side placed in contact with air during the casting stepwas caused to face the high pressure starting feed liquid, namely, a3500 ppm NaCl aqueous solution. It was found that the water flux was1.34 m³ /m².day and the NaCl rejection was 94.6%.

COMPARATIVE EXAMPLE 3

The procedures of Example 3 were repeated in the same manner except thatthe amount used of chlorosulfonic acid in step (ii) of Example 3 waschanged from 10.65 g to 3.2 g. The thus-synthesized sulfatedphenoxysulfone resin had a substitution degree of 0.13 group perrecurring unit. The separation capacity of a uniform (homogeneous)membrane prepared from this polymer was evaluated. It was found that thewater flux was 0.75×10⁻¹⁰ cm² /sec.atm and the NaCl rejection was 68.3%.

COMPARATIVE EXAMPLE 4

The procedures of Example 1 were repeated in the same manner except thatthe amount used of chlorosulfonic acid was changed from 21.3 g to 27.0g. The synthesized polymer had a substitution degree of 0.97 group perrecurring group. A uniform (homogeneous) membrane prepared from thispolymer was swollen when dipped in water, and therefore, the separationcapacity of the membrane could not be determined.

EXAMPLE 6

The uniform membrane prepared in step (ii) of Example 1 was dipped in a0.1 N sodium hydroxide aqueous solution for 72 hours, and the separationcapacity of the thus-treated membrane was evaluated in the same manneras described in step (iii) of Example 1 by using a 3500 ppm NaCl aqueoussolution. It was found that the water flux was 9.1×10⁻¹⁰ cm² /sec.atmand the NaCl rejection was 95.6%. Thus, it was confirmed that theseparation capacity of the membrane was substantially as high as theseparation capacity of the membrane that was not treated with the NaOHaqueous solution. By the NMR analysis, it was confirmed that in themembrane that was dipped in the NaOH aqueous solution, the sulfuric acidester as the substituent was converted from the pyridine salt to thesodium salt.

Comparative Example 5

When the uniform (homogeneous) membrane obtained in Comparative Example1 was dipped in a 0.1-N aqueous solution of sodium hydroxide for 72hours, the membrane was swollen, and therefore, the separation capacityof the membrane could not be determined.

EXAMPLE 7

A membrane equivalent to the asymmetric membrane of Example 5 was dippedat 20° to 25° C. for 64 hours in a liquid having a pH of 2.5 andcomprising 20 g of 40% glyoxal, 5 l of pure water and 1 g of 98%sulfuric acid, and was washed with water. The changes of the propertiesof the membrane caused by this dipping treatment are shown in Table 5.

EXAMPLE 8

A membrane equivalent to the asymmetric membrane of Example 5 was dippedin a liquid comprising 50 g of 38% aqueous formaldehyde, 350 ml of purewater and 100 g of 98% sulfuric acid at 70° to 80° C. for 2 hours, andthe thus-treated membrane was washed with water, neutralized with analkali and then washed with water again. The changes of the propertiesof the membrane caused by the above treatment are shown in Table 5.

                  Table 5                                                         ______________________________________                                        Changes Of Properties Of Membranes Caused By                                  Aldehyde Treatment                                                                    Ratio of Value after Treatment                                                to Value before Treatment                                                       NaCl Permea- Water Permea-                                                                              Tensile                                   Membrane  tion Ratio (%)                                                                             tion Coefficient                                                                           Modulus                                   ______________________________________                                        Membrane of                                                                   Example 7 0.6          0.9          1.6                                       Membrane of                                                                   Example 8 --           0            4                                         ______________________________________                                    

Note:

The NaCl permeation ratio (%) is a value calculated according to thefollowing formula:

NaCl permeation ratio (%)=100-NaCl rejection (%)

EXAMPLE 9

Di-n-propylamine salt of phenoxy resin sulfate was obtained in the samemanner as described in Example 1 step (i), except that the amount ofchlorosulfonic acid was 17.6 g (0.150 mole) and 42.5 g (0.412 mole) ofdi-n-propylamine was used in place of pyridine. The sulfation degree ofthe product was 0.55 from S analysis. Then, 40 g of the thus-producedpolymer was dissolved in a solution of 36 g of 2-methoxyethanol, 14 g ofacetone, 5 g of ethylene glycol and 5 g of water. An asymmetric membranewas obtained from the resulting solution in the same manner as describedin Example 5 and its properties as a membrane were examined. The resultswere a water flux of 0.64 m³ /m².day and NaCl rejection of 94.6%.

EXAMPLE 10

The preparation was effected in the same manner as described in Example9, except that 33.3 g (0.412 mole) of pyridine was used in place ofdi-n-propylamine. The water flux of the resulting membrane was 0.66 m³/m². day and the NaCl rejection thereof was 94.6%.

EXAMPLE 11

As asymmetric membrane was obtained in the same manner as described inExample 9, except that 62.6 g (0.412 mole) of1,8-diazabicyclo[5.4.0]undecene-7 was used in place of di-n-propylamine.The water flux and NaCl rejection of the resulting membrane were 0.57 m³/m².day and 94.6%, respectively.

EXAMPLE 12

An asymmetric membrane was obtained in the same manner as described inExample 9, except that 35.8 g of piperidine was used in place ofdi-n-propylamine. The water flux and NaCl rejection of the resultingmembrane were 0.71 m³ /m².day and 91%, respectively.

EXAMPLE 13

Di-n-propylamine salt of phenoxy resin sulfate was obtained in the samemanner as described in Example 1, step (i), except that the amount ofchlorosulfuric acid was 19.1 g and 42.5 g (0.412 mole) ofdi-n-propylamine was used in place of pyridine. The sulfation degree ofthe resulting polymer was 0.55 from S analysis. Forty grams of thethus-obtained polymer was dissolved in a solution of 30 g of2-methoxyethanol, 25 g of acetone and 5 g of water. An asymmetricmembrane was prepared from the solution in the same manner as describedin Example 5. The water flux and NaCl rejection of the resultingmembrane were 1.85 m³ /m².day and 92.2%, respectively.

EXAMPLE 14

The membrane obtained in Example 13 was immersed at 25° C. for 26 hoursin an aqueous solution containing 0.5 wt. % of dimethylolurea condensate(Mirben Resin SKH made by Showa Kohbunshi K.K.) in order to react. Then,after the membrane was immersed in 0.1 wt. % NaOH aqueous solution fortwo days, it was washed with water. Subsequently, its membraneproperties were examined in the same manner as described in Example 5.The water flux and NaCl rejection were 0.75 m³ /m².day and 90.0%,respectively. After the membrane was thus cross-linked, it was immersedin N,N'-dimethylformamide. It was observed that the membrane swelled to1.5 times size in 10 minutes. On the other hand, a membrane that had notbeen cross-linked was completely soluble in N,N'-dimethylformamide.

EXAMPLE 15

The same treatment as described in Example 14 was conducted except thatan aqueous solution containing 0.5 wt. % of hexamethoxymethylolmelamine(Mirben Resin SM607 made by Showa Kohbunshi K.K.), 0.1 wt. % of citricacid and 3.3 wt. % of acetone was used. The water flux and NaClrejection of the resulting membrane were 1.05 m³ /m².day and 89.0%,respectively. After the membrane was immersed in N,N'-dimethylformamidefor 10 minutes, it was found to be swelled to 2.5 times its originalsize. Further, the "--m" value was calculated when the membrane had beensubjected to a continuous operation for 400 hours. The "--m" value isobtained from the following equation ##EQU3## wherein F₀ is the initialwater permeation rate, F_(t) is a water permeation rate after continuousoperation continues for a period of time t, and t is a period of timefor operation (hours). As the "--m" value becomes smaller, it signifiesthat the decrease of the water permeation rate is smaller. The "--m"value of this case was 0.032, which is smaller than in the case with amembrane that has not been cross-linked, namely, 0.096.

EXAMPLE 16

The same treatment as described in Example 15 was conducted except thatglycerine-diglycidyl ether was used in place ofhexamethoxymethylolmelamine. The resulting membrane had a water flux of1.07 m³ /m².day and NaCl rejection of 88.9%. Then, it was immersed inN,N'-dimethylformamide for 10 minutes and it was found that it had beenswelled to a 1.6 times its original size. The "--m" value thereof was0.081 when operation had been continued for 400 hours.

EXAMPLE 17

Di-n-butylamine salt of phenoxy resin sulfate was obtained in the samemanner as described in Example 9 except that 54.1 g (0.412 mole) ofdi-n-butylamine was used in place of di-n-propylamine. The sulfationdegree thereof was 0.55 from S analysis. Forty grams of the resultingpolymer was dissolved in a solution of 36 g of 2-methoxyethanol, 14 g ofacetone, 5 g of ethyleneglycol and 5 g of water. An asymmetric membranewas obtained from the polymer solution in the same manner as describedin Example 5 and it was found to have a water flux of 0.38 m³ /m².dayand NaCl rejection of 91.0%.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A semipermeable membraneconsisting essentially of a water-insoluble, membrane-forming polymerhaving the formula ##STR8## wherein R and R' are halogen, nitro, methylor ethyl, X is a divalent group selected from the group consisting ofmethylene, ethylene, isopropylidene, ether (--O--), carbonyl (--CO--),sulfide (--S--), sulfoxide (--SO--) and sulfone (--SO₂ --), l and m areintegers of from 0 to 4, p is 0 or 1, and n is an integer of from 100 to1000,and wherein from 15 to 90% of said D groups are sulfuric acidgroups or salts thereof with an alkali metal, ammonia or anitrogen-containing basic organic compound, and the balance of said Dgroups are hydroxyl groups.
 2. A semipermeable membrane as set forth inclaim 1, wherein from 20 to 85% of said D groups are sulfuric acidgroups or said salts thereof.
 3. A semipermeable membrane as set forthin claim 1, wherein (X)_(p) is selected from the group consisting of SO₂and ##STR9## and l and m are zero.
 4. A semipermeable membrane as setforth in claim 1, which is formed on the surface of a porous membrane.5. A semipermeable membrane as set forth in claim 1, wherein saidnitrogen-containing basic organic compound is selected from the groupconsisting of di-n-propylamine, di-n-butylamine, pyridine,1,8-diazabicyclo [5.4.0] undecene-7 and piperidine.
 6. A semipermeablemembrane as set forth in claim 1, wherein said nitrogen-containing basicorganic compound is selected from the group consisting of ethanolamine,triethylamine and diethylamine.
 7. A polymer having the formula##STR10## wherein R and R' are halogen, nitro, methyl or ethyl and R andR' can be the same or different, X is methylene, ethylene,isopropylidene, --O--, ##STR11## --S--, --S(O)-- or --S(O) l and m areintegers of from 0 to 4, p is 0 or 1, n is integer of from 100 to 1000,and from 10 to 85 percent of the D groups of the polymer are hydroxyland the balance of the D groups of the polymer are ##STR12## wherein Mis an alkali metal and A is ammonia or a nitrogen-containing basicorganic compound.
 8. A polymer according to claim 7 in which p is
 1. 9.A polymer according to claim 8 in which X is --S(O)₂ -- or ##STR13## 10.A polymer according to claim 9 in which l and m are
 0. 11. Asemipermeable membrane as set forth in claim 1 wherein saidnitrogen-containing basic organic compound is selected from the groupconsisting of methylamine, ethylamine, propylamine, isopropylamine,butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine,isopentylamine, hexylamine, 2-ethylhexylamine, laurylamine,dimethylamine, diethylamine, dipropylamine, diisopropylamine,di-n-butylamine, N-methylethylamine, N-ethylisobutylamine,trimethylamine, triethylamine, N,N-dimethylpropylamine, tributylamine,N-ethyl-N-methylbutylamine, mono-, di- and tri-ethanolamine,diethylamino ethanol, urea, β-dimethylaminopropionitrile,tetramethylammonium tetraethylammonium, cyclohexylamine,N,N-dimethylcyclohexylamine dicyclohexylamine, aniline, o-toluidine,m-toluidine, p-toluidine o-ethylaniline, m-ethylaniline, p-ethylaniline,p-isopropylaniline, p-tert-butylaniline, N-methylaniline,N-ethylaniline, N,N-dimethylaniline, trimethylphenyl ammonium,ethyldimethylphenyl ammonium, benzylamine, α-methylbenzylamine, pyrrole,1-methylpyrrole, indole, pyridine, α-picoline, β-picoline, γ-picoline,2-ethylpyridine, quinoline, piperidine, 1-methyl piperidine,2-methylpiperidine, 1,8-diazabicyclo[5.4.0]undecene-7 and morpholine.12. A polymer according to claim 7 wherein said nitrogencontaining basicorganic compound is selected from the group consisting of methylamine,ethylamine, propylamine, isopropylamine, butylamine, isobutylamine,sec-butylamine, tert-butylamine, pentylamine, isopentylamine,hexylamine, 2-ethylhexylamine, laurylamine, dimethylamine, diethylamine,dipropylamine, diisopropylamine, di-n-butylamine, N-methylethylamine,N-ethylisobutylamine, trimethylamine, triethylamine,N,N-dimethylpropylamine, tributylamine, N-ethyl-N-methylbutylamine,mono-, di- and tri-ethanolamine, diethylaminoethanol, urea,β-dimethylaminopropionitrile, tetramethylammonium, tetraethylammonium,cyclohexylamine, N,N-dimethylcyclohexylamine, dicyclohexylamine,aniline, o-toluidine, m-toluidine, p-toluidine, o-ethylaniline,m-ethylaniline, p-ethylaniline, p-isopropylaniline, p-tert-butylaniline,N-methylaniline, N-ethylaniline, N,N-dimethylaniline, trimethylphenylammonium, ethyldimethylphenyl ammonium, benzylamine,α-methylbenzylamine, pyrrole, 1-methylpyrrole, indole, pyridine,α-picoline, β-picoline, γ-picoline, 2-ethylpyridine, quinoline,piperidine, 1-methylpiperidine, 2-methylpiperidine,1,8-diazabicyclo[5.4.0]undecene-7 and morpholine.